1. Field of the Invention
The present invention relates to electromagnetic relays, and in particular to electromagnetic relays having a one-piece coil body comprised of insulating material which has a movable contact disposed in a hollow interior thereof which makes and breaks with one or more stationary contacts also disposed within the core body.
2. Description of the Prior Art
Electromagnetic relays are known which include a one-piece coil body comprised of insulating material which have a ferromagnetic armature contact element disposed in a hollow interior thereof, the armature contact element being secured at one end by means of insertion into an end face which closes one end of the hollow interior. The movable contact is disposed approximately parallel to the longitudinal axis of the coil core body and makes and breaks with one or more stationary contact elements disposed at an opposite end of the coil core body which are partially embedded in an opposite wall which closes the other end of the hollow interior.
It is known from U.S. Pat. No. 3,522,564 to manufacture electromagnetic relays of the type described above by making the coil core body in two halves, with one of the cooperating contacts being embedded in each half and joining the halves during an assembly process. This conventional structure has the disadvantage that after the two coil body halves are joined, the cooperating contacts are no longer accessible for adjustment. If both cooperating contacts are injected in a one-piece coil body, the contacts can be made accessible for the purpose of cleaning by means of an opening at one end face of the coil body, however, the contact clearance cannot be adjusted in such a structure. A further disadvantage of such structures is that simultaneous injection molding of the two contact plates is difficult during manufacture.